Maintained by Robin Tecon, microbiologist and postdoctoral researcher at the Swiss Federal Institute of Technology Zürich. This blog is about bacteria (and other microbes) and the scientists who study them.

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Monday, November 04, 2013

Our world
is a quite green world: a sea of trees, bushes, grasses, or, if you happen to
live in the Midwest, corn fields… What is less obvious, though, is the fact
that this green vastness harbors a huge community of microbes. Yeasts and
filamentous fungi are often found on plant surfaces, but the most numerous
inhabitants are first and foremost bacteria. Indeed, a centimeter square of
leaf can contain as many as 10 millions of them! No worries, most of them are
harmless to us or their plant hosts. On the contrary, many are required to
maintain a healthy plant environment, by stimulating plant growth or by
preventing the plant colonization by pathogens (they compete for the same space
and the same resources).

Because
plants are so vital to us (think food, raw materials, landscapes, etc.), there
is a real interest in understanding what the microbial contribution to the
plant ecosystem is. One lingering question, for instance, is how bacteria colonize
the surface of leaves (what we call the phyllosphere). What we do know is that bacteria on leaf surfaces appear as clusters of cells, rather than an even layer of bacteria covering the
surface; the mechanisms that lead to this colonization pattern, however, is not
well understood. I have already written about this question in a previous post that dealt with the use of bacterial bioreporters. Another way to explore these
mechanisms of cluster formation is computer-based modelling, which enables us
to test different scenarios and compare it with what has been observed on real
plants.